纤维增强树脂基复合材料激光切割热影响探析

Laser Cutting Induced Heat Affected Zone in Fiber Reinforced Polymer: A Comparative Analysis

作为一类典型难加工材料,实现以碳纤维增强树脂基复合材料(CFRP)、芳纶纤维增强树脂基复合材料(AFRP)为代表的纤维增强树脂基复合材料(FRP)的高精密、高质量加工是业界的追求目标。初探了激光脉冲宽度、波长对于典型FRP切割边缘热影响区的影响规律,比较了不同FRP材料精密切割对于激光参数需求的异同。发现纳秒激光、连续激光等传统激光因加工热效应明显而不适合精密切割,而皮秒激光、飞秒激光等超快激光可以实现热影响区宽度仅0.01mm^0.1mm量级的高质量切割,且热影响区宽度几乎不依赖于脉冲宽度;缩短超快激光波长有利于减小AFRP材料的热影响区宽度,但对于CFRP材料则不明显。考虑到高功率皮秒激光一般比对应的飞秒激光更经济,可使用倍频后得到的短波长皮秒激光实现对AFRP的精密切割,对于CFRP则考虑本征波长的皮秒激光即可。

As a typical hard-to-machine material,it is the goal of the industry to realize high precision and high quality processing of fiber reinforced polymer(FRP)represented by carbon fiber reinforced polymer(CFRP)and aramid fiber reinforced polymer(AFRP).Here the influence of laser pulse width and wavelength on heat-affected zone of typical FRP composites is discussed.The differences and similarities in requirements of precision cutting of different FRP materials are discussed.It is proved that traditional lasers,such as nanosecond laser and continuous laser,are unsuitable for precision cutting because of the serious thermal effects,while ultrafast lasers(picosecond lasers and femtosecond lasers)are not.The typical heated-affected-zone size,almost independent on the ultrafast laser pulse-width,can be as small as 0.01 mm^0.1 mm.Shortening the wavelength of ultrafast laser is beneficial to reducing the size of heat affected zone of AFRP material,but not obvious for CFRP material.Since high power picosecond lasers are more economical than femtosecond lasers,the short-wavelength picosecond laser(via frequency doubling/tripling)is proposed for AFRP precision cutting,and picosecond laser with intrinsic wavelength is proposed for CFRP precision cutting.